In a telecommunications network, an alarm is generated when some sort of anomalous condition arises in a component forming part of the network. Such an alarm is transmitted in message form through the network to network surveillance personnel (or "craftspeople") working at various network surveillance workstations or to a higher level management system.
Large networks can quickly overwhelm users with large amounts of alarm information. Accordingly, a mechanism is needed to allow the users of the system to track which alarms have already been looked at so that when a new alarm comes in it can be investigated as soon as is appropriately possible. This is referred to as alarm acknowledgement.
Various existing alarm acknowledgement schemes exist. In one scheme, when an alarm message is received by a network surveillance workstation, some text is highlighted on a screen. After a particular operator acknowledges the alarm, the highlighting is removed. A problem with this system is that the highlighting is only removed from the particular workstation at which the particular operator was working. Assuming the alarm message was sent to a number of such workstations, the other workstations will still show the alarm as being in an unacknowledged state.
In existing systems, alarm information is stored in one or more non-volatile repositories which might be disk drives for example. This is to provide an aspect of survivability. When a system fails, after recovery the information will still be in the non-volatile repository. A problem with this is that if the non-volatile repository or links to the non-volatile repository malfunction, then the alarm repository becomes unavailable to network operators. Furthermore, it is known that non-volatile storage mechanisms such as disk drives for example can be very slow. If many alarms are being generated in a short amount of time, disk access can become a bottleneck.